Notch-leaved phacelia ( phacelia crenulata ) is a lovely little purple wild flower which grows across the desert southwest from California to Texas. The plant is typically between three to twenty-four inches in height. The flower is also known by several different names including, notch-leaf scorpion-weed, notch-leaved phacelia, cleftleaf wildheliotrope, and heliotrope phacelia.
The Purple Notchleaf Phacelia, scientifically known as Phacelia crenulata (also called Notch-leaf Phacelia, Notch-leaf Scorpion-weed, or Cleftleaf Wild Heliotrope), is one of the most iconic annual wildflowers of the Mojave Desert. In Death Valley National Park—the hottest and driest place in North America—this species transforms barren landscapes into vibrant purple carpets during years with sufficient winter rainfall. It is especially prominent in “superbloom” events, where it blooms alongside bright-yellow Desert Gold (Geraea canescens) to create striking color contrasts on alluvial fans and valley floors.
As of March 2026, Death Valley is experiencing one of the best superbloom displays in a decade, with P. crenulata contributing heavily to the purple displays visible from areas like Badwater Road and Furnace Creek.
Taxonomy
- Scientific Name: Phacelia crenulata Torr. ex S. Watson
- Family: Hydrophyllaceae (Waterleaf family; sometimes placed in Boraginaceae)
- Order: Boraginales
- Higher Classification: Angiosperms (flowering plants), Eudicots, Asterids
The species includes several varieties that intergrade:
- var. ambigua (rangewide, larger purple flowers)
- var. crenulata (California to Utah)
- var. minutiflora (smaller flowers, sometimes lavender-blue with white throats).
Morphological Description
Phacelia crenulata is an aromatic annual herb, typically 7–60 cm tall (up to 80 cm or ~30 inches in favorable conditions), with erect stems that are sparsely to densely covered in stiff, glandular hairs.
Leaves: Oblong, 2–12 cm long, with wavy, lobed, or distinctly notched/scalloped (crenulate) margins—giving the plant its common name “Notchleaf.” The basal leaves are largest; upper leaves become smaller and more reduced.
Flowers: Arranged in coiled cymes (scorpioid inflorescences) that uncoil as they bloom, resembling a scorpion’s tail. Individual flowers are bell-shaped, ½–1 cm long, with deep violet-to-purple petals (sometimes blue) and a white or pale throat. Stamens and style protrude prominently from the corolla.
Fruit: A small, rounded capsule containing several seeds.
The entire plant is glandular-hairy and emits a distinctive (sometimes unpleasant) scent.
Habitat and Distribution
Phacelia crenulata is native to arid regions of the southwestern United States (Arizona, California, Colorado, New Mexico, Nevada, Texas, Utah) and northern Mexico. It has a rare antitropical (disjunct) distribution, also occurring in parts of South America (southern Peru, western Bolivia, northern Chile).
In Death Valley National Park, it prefers open, sandy, gravelly, or rocky soils on alluvial fans, foothills, and low-elevation desert washes. It commonly appears from mid-February to mid-April at lower elevations (below ~1,000 m), often in disturbed areas or alongside other desert annuals.
Ecology, Life Cycle, and Adaptations
As a desert annual, P. crenulata is an “ephemeral” species whose life cycle is tightly linked to winter precipitation. Seeds lie dormant in the soil for years and germinate rapidly after adequate rain, allowing the plant to grow, flower, set seed, and die before the extreme summer heat and drought return.
Key adaptations:
- Glandular hairs that may reduce water loss and deter herbivores.
- Coiled inflorescences that protect developing flowers.
- Rapid phenology synchronized with brief windows of moisture.
It is highly valuable to native bees as a pollen and nectar source.
Note on human interaction: Like many phacelias, the plant can cause contact dermatitis (skin rash similar to poison oak) in sensitive individuals due to its glandular secretions. Avoid handling if you have sensitive skin.
Conservation Status
Phacelia crenulata is considered “Secure” by NatureServe and faces no major conservation threats. In Death Valley, it benefits from the park’s protection but remains sensitive to off-road vehicle traffic, climate-driven changes in rainfall patterns, and invasive species competition. It is a flagship species for public appreciation of desert biodiversity during superbloom events.
Summary
The Purple Notchleaf Phacelia exemplifies the resilience and beauty of Mojave Desert flora. Its vivid purple blooms, triggered by rare wet winters, turn Death Valley’s harsh landscape into a temporary floral paradise—reminding observers of the delicate balance of water, temperature, and life in one of Earth’s most extreme environments.
Key Viewing Tips for Death Valley (March–April 2026): Look along low-elevation roads and washes near Furnace Creek, Badwater, and the East Entrance for the best displays of purple P. crenulata mixed with yellow desert gold.
This report is based on botanical records from the National Park Service, botanical databases, and field observations during active bloom periods.
